After manufacture, a data processing device is typically tested to ensure the device behavior matches a specification. For a typical test, a test pattern is applied to an input of the data processing device and a resultant output pattern compared to an expected output pattern. The test pattern typically tests only a portion of the possible states of the data processing device. Accordingly, the data processing device is tested with a variety of different test patterns in order to increase the number of possible states tested. However, because of the complexity of modern data processing devices, it can be difficult to test all portions of a device with a set of test patterns. For example, it can be problematic to test memory and associated devices using a set of general test patterns.
The use of the same reference symbols in different drawings indicates similar or identical items.